Right click to dismiss most menus

**Issue by [chaorace](https://github.com/chaorace)**
_Sunday Oct 30, 2016 at 16:23 GMT_
_Originally opened as https://github.com/CQUI-Org/cqui/issues/25_

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I'd like pretty much every screen and panel that can be dismissed to have a RMB bind for quick closing. For example: Tech/Civic trees, Gov, Religion, and GP views, Rankings, Reports, City-States and Trade views as well. If possible, also work on a way to quickly exit leader dialogs that don't require interacting (denounce, compliment, etc)

The issue lists the Tech/Civic trees, Government, Religion, Great People, Rankings, Reports, City-States, Trade, and leader-dialog views as targets. Start by locating how these views currently dismiss and handle right-click input, then verify that each listed dismissible view closes without affecting other interactions. The requested leader-dialog behavior also needs a clear test or manual verification path.

Written by the indexing model from the issue text.